Abstract

A β-glucosidase from Phoma sp. KCTC11825BP isolated from rotten mandarin peel was purified 8.5-fold with a specific activity of 84.5 U/mg protein. The purified enzyme had a molecular mass of 440 kDa with a subunit of 110 kDa. The partial amino acid sequence of the purified β-glucosidase evidenced high homology with the fungal β-glucosidases belonging to glycosyl hydrolase family 3. Its optimal activity was detected at pH 4.5 and 60oC, and the enzyme had a half-life of 53 h at 60oC. The Km values for p-nitrophenyl-β-D-glucopyranoside and cellobiose were 0.3 mM and 3.2 mM, respectively. The enzyme was competitively inhibited by both glucose (Ki=1.7 mM) and glucono-δ-lactone (Ki=0.1 mM) when pNPG was used as the substrate. Its activity was inhibited by 41% by 10 mM Cu2+ and stimulated by 20% by 10 mM Mg2+.

title = "Purification and characterization of an extracellular β-glucosidase produced by phoma sp. KCTC11825BP isolated from rotten mandarin peel",

abstract = "A β-glucosidase from Phoma sp. KCTC11825BP isolated from rotten mandarin peel was purified 8.5-fold with a specific activity of 84.5 U/mg protein. The purified enzyme had a molecular mass of 440 kDa with a subunit of 110 kDa. The partial amino acid sequence of the purified β-glucosidase evidenced high homology with the fungal β-glucosidases belonging to glycosyl hydrolase family 3. Its optimal activity was detected at pH 4.5 and 60oC, and the enzyme had a half-life of 53 h at 60oC. The Km values for p-nitrophenyl-β-D-glucopyranoside and cellobiose were 0.3 mM and 3.2 mM, respectively. The enzyme was competitively inhibited by both glucose (Ki=1.7 mM) and glucono-δ-lactone (Ki=0.1 mM) when pNPG was used as the substrate. Its activity was inhibited by 41% by 10 mM Cu2+ and stimulated by 20% by 10 mM Mg2+.",

T1 - Purification and characterization of an extracellular β-glucosidase produced by phoma sp. KCTC11825BP isolated from rotten mandarin peel

AU - Choi, Jung Youn

AU - Park, Ah Reum

AU - Kim, Yong Jin

AU - Kim, Jae-Jin

AU - Cha, Chang Jun

AU - Yoon, Jeong Jun

PY - 2011/5/1

Y1 - 2011/5/1

N2 - A β-glucosidase from Phoma sp. KCTC11825BP isolated from rotten mandarin peel was purified 8.5-fold with a specific activity of 84.5 U/mg protein. The purified enzyme had a molecular mass of 440 kDa with a subunit of 110 kDa. The partial amino acid sequence of the purified β-glucosidase evidenced high homology with the fungal β-glucosidases belonging to glycosyl hydrolase family 3. Its optimal activity was detected at pH 4.5 and 60oC, and the enzyme had a half-life of 53 h at 60oC. The Km values for p-nitrophenyl-β-D-glucopyranoside and cellobiose were 0.3 mM and 3.2 mM, respectively. The enzyme was competitively inhibited by both glucose (Ki=1.7 mM) and glucono-δ-lactone (Ki=0.1 mM) when pNPG was used as the substrate. Its activity was inhibited by 41% by 10 mM Cu2+ and stimulated by 20% by 10 mM Mg2+.

AB - A β-glucosidase from Phoma sp. KCTC11825BP isolated from rotten mandarin peel was purified 8.5-fold with a specific activity of 84.5 U/mg protein. The purified enzyme had a molecular mass of 440 kDa with a subunit of 110 kDa. The partial amino acid sequence of the purified β-glucosidase evidenced high homology with the fungal β-glucosidases belonging to glycosyl hydrolase family 3. Its optimal activity was detected at pH 4.5 and 60oC, and the enzyme had a half-life of 53 h at 60oC. The Km values for p-nitrophenyl-β-D-glucopyranoside and cellobiose were 0.3 mM and 3.2 mM, respectively. The enzyme was competitively inhibited by both glucose (Ki=1.7 mM) and glucono-δ-lactone (Ki=0.1 mM) when pNPG was used as the substrate. Its activity was inhibited by 41% by 10 mM Cu2+ and stimulated by 20% by 10 mM Mg2+.